title: Activated T cells induce up-regulation of Fas antigen in cultured endothelial cells.
abstract: Recent evidence has shown that apoptotic cells are present in human atherosclerotic lesions. However, the molecular mechanism of the induction of apoptosis in atherosclerotic lesions is not clear. Since T cells are present in almost all stages of atherosclerosis, we examined whether T cells can modulate the expression of Fas, a death signal, in endothelial cells (ECs), using a coculture system. Human umbilical vein ECs were cultured alone or cocultured with human peripheral T cells activated with phorbol myristate acetate and ionomycin. Flow cytometric (FACscan) analysis showed that Fas antigen was up-regulated in ECs when ECs were cocultured for 24 h with activated T cells. However, Fas antigen was not up-regulated in ECs cocultured with non-activated T cells. The up-regulation of Fas antigen induced by coculturing ECs with activated T cells was partially, but significantly, neutralized by antibody against interferon-gamma (IFN-gamma). Actually, incubation with IFN-gamma induced a dose-dependent increase in the level of Fas antigen in ECs cultured alone. These findings indicate that activated T cells induce up-regulation of Fas antigen in ECs. Thus, the Fas system induced by activated T cells could participate in the mechanism of EC injury in atherosclerotic lesions.
authors.affiliation: Department of Geriatric Medicine, Osaka University Medical School, Suita, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Fukuo
authors.forename: T
authors.initials: T
authors.lastname: Suhara
authors.forename: T
authors.initials: T
authors.lastname: Nakahashi
authors.forename: S
authors.initials: S
authors.lastname: Hata
authors.forename: M
authors.initials: M
authors.lastname: Shimizu
authors.forename: T
authors.initials: T
authors.lastname: Niinobu
authors.forename: S
authors.initials: S
authors.lastname: Morimoto
authors.forename: T
authors.initials: T
authors.lastname: Ogihara
mesh_terms: D017209:Apoptosis / Q000502:physiology*; D002478:Cells, Cultured; D018920:Coculture Techniques; D004730:Endothelium, Vascular / Q000166:cytology* / Q000502:physiology; D005434:Flow Cytometry; D006801:Humans; D008213:Lymphocyte Activation; D013601:T-Lymphocytes / Q000502:physiology*; D014471:Umbilical Veins / Q000166:cytology; D015854:Up-Regulation / Q000502:physiology*; D019014:fas Receptor / Q000502:physiology*
chemical_list: D019014:fas Receptor